Few urban sites in the French-speaking part of Switzerland have generated such controversy, and for such high stakes, as the Flon district in the centre of the city of Lausanne. From the disused industrial warehouses of the early twentieth century to the artists' and architects' studios and nightclubs, the Flon has had a rich and turbulent history. The redevelopment of the quarter as a whole has been the subject of numerous urban design competitions and debates, all of which proved abortive. Business life and commercial logic having reasserted their prerogatives, the quarter is currently in the midst of a process of mutation and improvement. This renewal, unfortunately not always successful, is taking place little by little, building by building, and is tending to erase the specificity of this former industrial zone.

Fortunately, as from this year, the Flon can boast an object that is symbolic of the commercial renewal of the district and of high architectural quality. Designed by local architects Brauen and Wälchli, La Miroiterie shopping mall is at once solid and light. It has a simple shape, a parallelepiped, whose gently undulating facade vibrates with a soft glow as daylight wanes. Positioned in front of a large plaza, the new shopping centre lends the whole quarter an original aspect.

The La Miroiterie building is an exemplary specimen of inflatable construction. Wrapped around a concrete and steel load-bearing frame, the building's outer walls are made of cushions filled with air. While very insubstantial in appearance, the walls meet the strict heat insulation standards that apply in Switzerland.

The building's envelope is composed of four layers of air-filled membranes that are monitored automatically and maintained at a constant pressure. Stretched between the diagonals of the structure, the envelope forms a composition of vast translucent pneumatic cushions perforated by glazed openings. This breathing skin provides the building's heat insulation and also gives the interior spaces a particularly soft light. Placed on top of a glazed base that is slightly set back from the outer walls, the inflated volume seems to float above the ground.

This impression of floating and of precarious balance is further emphasized by the building's load-bearing frame. Built in exposed concrete, the frame sits atop an existing car park with a single central bearing span. From this median line on the ground floor, the framework of pillars spreads and widens on each storey in order to support the floor slabs. Thanks to this tree-like configuration, loads are transferred from the periphery to the centre, from the top to the bottom, like a spinal column upon which the weight of the entire building is concentrated. The triangulations of the metal frame of the facade stabilize the load-bearing structure and stiffen the whole construction. Far from being a graphic formalism, the triangular shape of the structure and of the facade is the result of a rigorous and restrictive structural concept.

This structural regularity delivers flexible open plans on each floor. A lift and escalator shaft links the various levels vertically. Yet each of these floors is unique because of the position and the angle of the load-bearing pillars. The arrangement of large glazed openings adds to the differentiation among the levels and facilitates orientation through the diagonals that demarcate the spaces.

Until recently the shops of La Miroiterie du Flon were vacant, but now tenants are about to move in these magnificent commercial premises.